The future of current attempts to re-establish devolution in Northern Ireland was cast into serious doubt after Ulster Unionist leader Mr David Trimble yesterday withdrew his party from the review of the Belfast Agreement.
Mr Trimble, who is meeting the British Prime Minister, Mr Tony Blair, in Downing Street today, insisted he would not engage further in the review until the British and Irish governments agreed to sanctions against Sinn Féin over the alleged IRA attack on Mr Bobby Tohill.
The Taoiseach said last night he hoped to talk to Mr Trimble today, and would try to persuade him to go back to the review. He said he was disappointed at the UUP leader's decision, although he knew last week that he had intended to withdraw.
"I had hoped that they had been persuaded to stay on," Mr Ahern told reporters last night. "We know from the past that suspensions do nothing for the short-term, medium-term or the long-term".
Mr Trimble said that his request for sanctions against Sinn Féin was rejected by the Minister for Arts, Sports and Tourism, Mr O'Donoghue; the Minister of State for Foreign Affairs, Mr Tom Kitt; and the Northern Secretary, Mr Paul Murphy, whom he met in the review at Stormont yesterday. "Until we get a positive response on this matter we are not going to participate further in the ... review," said Mr Trimble.
Although pulling out of this process, he added that he would continue to meet the governments and the other parties. Mr Trimble is also seeking a meeting with the Taoiseach, Mr Ahern, to discuss the fallout from the Tohill incident.
The Sinn Féin leaders Mr Gerry Adams and Mr Martin McGuinness met Mr Blair in London yesterday, and the DUP leader, the Rev Ian Paisley, and SDLP leader, Mr Mark Durkan, are to meet Mr Blair next week.
But despite the high-level political contacts, the British and Irish governments are concerned that the review will grind to a halt, and that the next significant attempt to reactivate the institutions of the agreement won't take place until the autumn.
Mr Trimble said he would have a simple message for Mr Blair today.
"The fundamental principle on which this process is based is a commitment to peace and democracy, and that principle needs to be vindicated," he said.
The DUP, while refusing to deal directly with Sinn Féin, is to remain in the review.
However, plans by the governments to organise a round-table meeting of the participants for next Tuesday to deal with the single issue of paramilitarism must now be abandoned, Dublin and London have conceded.
The DUP, which also met Mr O'Donoghue and Mr Murphy yesterday, accused Mr Trimble of acting foolishly and out of "pique".
The DUP MP Mr Jeffrey Donaldson said Mr Trimble was effectively giving the IRA a veto over the process by his withdrawal. "I simply can't understand why David Trimble allows the IRA to dictate his strategy. Why is it every time the IRA does something David Trimble alters course," he said.
Sinn Féin and London described Mr Adams's and Mr McGuinness's meeting with Mr Blair as a "touching base" exercise. Sinn Féin's chief negotiator Mr McGuinness said his party was perfectly willing to deal with the issue of paramilitarism, and that Sinn Féin had a major concern about loyalist violence.
Earlier at the review, West Belfast MLA Ms Bairbre de Brún, of Sinn Féin, presented the governments with a dossier on loyalist paramilitary attacks on nationalists.
She said Mr Trimble, by withdrawing from the review, was guilty of "posturing without substance".
"This is part of Mr Trimble's competition with the DUP. He is attempting to compete with the DUP on Ian Paisley's ground. It is the wrong approach," added Ms de Brún.
Also criticising Mr Trimble's decision to walk away from the review, the SDLP leader Mr Durkan said: "David Trimble is making a serious political mistake in walking away from the review. At a time when the focus should be on unacceptable paramilitary activity, it is instead on his inexplicable tactics."
